Rio Neuquen
1984
USA
Rest of the world
Packaged
HNS Spilt
Aluminium phosphideSolid
AlP
Amount Spilt (T)10.5
CAS Number20859-73-8
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Physical Behaviour (SEBC code)
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-
Pollution Category (MARPOL Annex 2)
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4.3
Class according to IMDG code
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-
Subsidiary Risk Class according to IMDG code
-
Classification as Marine Pollutant
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iv
HNS Classification (2010 HNS Convention)
Fate and weathering facts observed/reported
Seven tousand flasks with 1.497 kg of aluminium phosphide each. The substance is a toxic biocide and is used as a fumigant to control insects. It is acutely toxic when ingested and reacts with water or atmospheric moisture to emit phosphine. The latter is a highly toxic and reactive gas. Phosphine is also extremely toxic and flammable and is often contaminated by small amounts of diphosphine that is likely to auto ignite in air and cause explosion, even at ambient temperature. Although through evaluation, ocean dumping of AlP was accepted as a safe and satisfactory measure. The hazardous atmosphere aboard the ship was continuously monitored by means of Draeger tubes and a HNU photoionization unit. The flasks were transferred to 230-litre overpacks. Powdered lime was added as packing buffer and desiccant material. Lids were left loose on the drums to avoid accumulation of gas and reduce the risk of explosion. After careful reviewing of several different disposal options, ocean dumping was decided.